1. Field of the Invention
The present invention relates to an automatically locking fishplate, which is more particularly intended to join portions or sections of cableway in the form of welded trelliswork, end to end.
2. History of the Related Art
Portions of cableway in the form of welded trelliswork, presenting the form of a gutter and assembled on one another to support various conduits and cables and in particular electric cables, has been known for a long time. Each portion of cableway is constituted by U-shaped transverse wires on which are welded, on the one hand on the bottom, longitudinal wires and, on the other hand on the outside of the branches of the U, marginal wires.
In the present state of the art, screw devices such as fishplates are used for assembling the portions of cableway end to end, which fishplates are disposed on the outside of the branches of the transverse wires and which are maintained by counter-fishplates and bolts.
French Patent Application No. 2 209 219 discloses fishplates which are rigid in their central part and elastic in their end parts. These latter respectively comprise a fold in U-form extended by an inclined tab. These fishplates are installed with the aid of a tool between two longitudinal wires or two marginal wires of two portions of cableway, with the result that each of their ends engages on a transverse wire of each of the two portions.
Such fishplates are made of an elastic material, for example spring steel which, after having been placed in position, does not enable the portions of cableway to be maintained perfectly aligned when they are placed under load. Moreover, the use of a particular tool does not facilitate the use of these fishplates, as they must be considerably elongated in order to be able to look on the transverse wires of the two portions to be joined.
The improvements according to the present invention aim at overcoming the drawbacks set forth hereinabove and at producing a fishplate comprising a particular structure allowing two portions of cableway placed end to end to be automatically locked.